NEW ORLEANS -- BP's broken well was leaking oil and gas again Monday for the first time since the company capped it last week, but the Obama administration's spill chief said it was no reason for alarm. The stopper was left in place for now.
Ever since the cap was used to bottle up the oil last week, engineers have been watching underwater cameras and monitoring pressure and seismic readings to see whether the well would hold or spring a new leak, perhaps one that could rupture the seafloor and make the disaster even worse.
Small amounts of oil and gas started coming from the cap late Sunday, but ''we do not believe it is consequential at this time,'' retired Coast Guard Adm. Thad Allen said.
Also, seepage from the seafloor was detected over the weekend less than two miles away, but Allen said it probably has nothing to do with the well. Oil and gas are known to ooze naturally from fissures in the bottom of the Gulf of Mexico.
At an afternoon briefing in Washington, Allen said BP could keep the cap closed at least another 24 hours, as long as the company remained alert for leaks.
BP and the government are at odds over the company's desire to simply leave the cap in place and employ it like a giant cork in a bottle until a relief well being drilled deep underground can be used to plug up the well permanently.
Allen had made it clear his preference would be to use the cap instead to capture the oil and pipe it to tankers on the surface to reduce the slight chance that the buildup of pressure inside the well could cause a new blowout.
But opening up the cap in that way would require releasing millions more gallons of oil into the ocean for a few days during the transition -- a spectacle BP apparently wants to avoid.
Allen said BP and the government are still trying to understand why pressure readings from the well are lower than expected. He offered two possible explanations: The reservoir the oil is gushing from is dwindling, or there is an undiscovered leak somewhere down in the well.
''I'm not prepared to say the well is shut in until the relief well is done,'' which is still several weeks away, Allen said. ''There are too many uncertainties.''
BP and the Coast Guard learned that lesson the hard way after they initially said no oil was coming from the site of the Deepwater Horizon rig after it exploded April 20, killing 11 workers. Even after it became clear there was a leak, the company and its federal overseers drastically underestimated its size for weeks.
Robert Carney, a Louisiana State University expert on biological oceanography, said the seepage is far enough away from the well that it could be occurring naturally.
''You have little bubbles rising up from the bottom frequently; that's the methane gas'' he said. ''Oil would be a little black dot, more difficult to see. But both escape into the water regularly.''